Related Experiment Video
Updated: Aug 30, 2026

Removal of Arsenic Using a Cationic Polymer Gel Impregnated with Iron Hydroxide
Published on: June 28, 2019
Mobilization of arsenic from subsurface sediments by effect of bicarbonate ions in groundwater
Hossain M Anawar1, Junji Akai, Hiroshi Sakugawa
1Graduate School of Science and Technology, Niigata University, Ikarashi 2-no-cho, Niigata 950-2181, Japan. hma201@yahoo.com
Abstract:
Arsenic leaching by bicarbonate ions has been investigated in this study. Subsurface sediment samples from Bangladesh were treated with different carbonate and bicarbonate ions and the results demonstrate that the arsenic leaching efficiency of the carbonate solutions decreased in the order of Na2CO3>NaHCO3>BaCO3>MnCO3. Sodium carbonate and bicarbonate ions extracted arsenic most efficiently; Na2CO3 leached maximum 118.12 microg/l of arsenic, and NaHCO3, 94.56 microg/l of arsenic from the Ganges delta sediments after six days of incubation. The arsenic concentrations extracted in the batch experiments correlated very well with the bicarbonate concentrations. The kinetics study of arsenic release indicates that arsenic-leaching rate increased with reaction time in bicarbonate solutions. Bicarbonate ions can extract arsenic from sediment samples in both oxic and anoxic conditions. A linear relationship found between arsenic contents in core samples and those in leachates suggests that dissolved arsenic concentration in groundwater is related to the amount of arsenic in aquifer sediments. In batch experiment, bicarbonate solutions effectively extracted arsenic from arsenic adsorbed iron oxyhydroxide, reflecting that bicarbonate solutions may mobilize arsenic from iron and manganese oxyhydroxide in sediments that are ubiquitous in subsurface core samples. Carbonate ion may form complexes on the surface sites of iron hydroxide and substitute arsenic from the surface of minerals and sediments resulting in release of arsenic to groundwater. Like in the batch experiment, arsenic and bicarbonate concentrations in groundwater of Bangladesh correlated very well. Therefore, bicarbonate leaching is presumed to be one important mechanism to mobilize arsenic in bicarbonate dominated reducing aquifer of Bangladesh and other parts of the world as well.
More Related Videos
06:52Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron (Oxy)Hydroxides, Trace Elements, and Bacteria
Published on: December 19, 2017
10:05Integrated Field Lysimetry and Porewater Sampling for Evaluation of Chemical Mobility in Soils and Established Vegetation
Published on: July 4, 2014
Related Concept Videos
Microbial Bioremediation of Uranium
Acid Mine Drainage
Microbial Leaching
Bioremediation
Microbes and the Sulfur Cycle
Microbial Mats